The present invention relates to azabicyclo derivatives in their labelled and unlabelled form. Furthermore, the present invention relates to the use of said derivatives in their labelled or unlabelled form in diagnostic methods, in particular for in vivo receptor imaging (neuroimaging).
WO 9713770 discloses 8-azabicyclo[3.2.1]oct-2-ene derivatives which are re-uptake inhibitors for the monoamine neurotransmitter serotonine (5-hydroxy-tryptamine, 5-HT) and therefore useful in the treatment of disorders or diseases which are caused, at least in part, by increase or decrease of the endogenous serotonine levels. Such disorders or diseases are e.g., depression and related disorders, obsessive compulsive disorders, panic disorders, memory deficits, attention deficit, hyperactivity disorder, obesity, anxiety and eating disorders.
Monoamine neurotransmitters (i.e. serotonine, dopamine, and noradrenaline) are produced in neurons and are released into the synaptic cleft upon stimulation of the presynaptic neuron. The neurotransmitter molecules can diffuse through the cleft and then bind to specific receptor molecules (transporters) located in the postsynaptic cell membrane. Binding to these receptors results in polarisation of the cell, i.e. transduction of the stimulus. The removal (or inactivation) of monoamine neurotransmitters from the synaptic cleft occurs mainly by a re-uptake mechanism into presynaptic nerve terminals. By inhibiting the re-uptake an enhancement of the physiological activity of monoamine neurotransmitters occurs.
Major depression is a common disorder, affecting approximately 1 in 6 individuals at some point in their lives. The pathophysiology of depression is poorly understood so far, and several neurotransmitters have been implicated in the pathophysiology of major depression. Inhibitors that block noradrenaline and serotonine re-uptake are currently used as pharmaceuticals in anti-depressant therapy. Several lines of preclinical and clinical evidence indicate that an enhancement of serotonine-mediated neurotransmission might underlie the therapeutic effect of the most recent and currently used drugs in anti-depressant therapy, such as fluoxetine, citalopram and paroxetine [P. Blier and C de Montigney; TIPS (Review) 1994 15 220-225].
Paradoxically, serotonine re-uptake inhibitors block the serotonine transporter within minutes after application whereas their full anti-depressant effect is seen only after three to four weeks of treatment, indicating that re-uptake inhibition per se is not responsible for the anti-depressant response, but rather that further adaptive changes underlie and/or contribute to their therapeutic effect [P. Willner; Int. Review of Psychiatry 1990 2 141-156].
The serotonergic neural system of the brain has been shown to influence a variety of physiologic functions, and disturbance of this system has been made responsible for a variety of diseases and disorders such as eating disorders, depression, obsessive compulsive disorders, panic disorders, alcoholism, pain, memory deficits and anxiety. Included among these disorders are depression and related disorders such as pseudodementia or Ganser""s syndrome, migraine, pain, bulimia, obesity, pre-menstrual syndrome or late luteal phase syndrome, alcoholism, tobacco abuse, panic disorder, anxiety, post-traumatic syndrome, memory loss, dementia of ageing, social phobia, attention deficit hyperactivity disorder (ADHD syndrome), chronic fatigue syndrome, premature ejaculation, erectile dysfunction, anorexia nervosa, disorders of sleep, autism, mutism or trichotillomania.
Currently the standard method for the diagnosis of depression is a consultation between physician e.g., psychiatrists and patient in order to evaluate the patient""s emotional life. It is characteristic for depressed patients e.g. to lack initiative and interest, to possess a general feeling of sadness, and to have a feeling of guilt and worthlessness, to lack appetite and libido, and to suffer from sleeplessness. These symptoms can occur temporarily and with different intensity which makes it very difficult to determine the appropriate diagnosis and therapy. Therefore, psychiatrists have looked for objective laboratory or clinical tests that could confirm the diagnosis and possibly predict a response to treatment.
Recent research has focused on the biochemical backgrounds of the depression syndrome. It has been found that measurements of the regional cerebral blood-flow (rCBF) can be used to diagnose depression. In brains of depressed patients three areas showed significantly reduced rCBF (left dorsolateral prefrontal cortex, the left anterior cingulate cortex and the left angular gyrus). When depression is combined with cognitive impairment a decreased rCBF in the left medial prefrontal cortex and increased rCSF in the right cerebral vermis has been detected [Bench C J, Friston K J, Brown R G, Scott L C, Frackowiak R S and Dolan R J: The anatomy of melancholia-focal abnormalities of cerebral blood flow in major depression; Psychol-Med. 1992 22 (3) 607-15; and Dolan R J, Bench C J, Brown R G, Scott L C, Friston K J and Frackowiak-R S: Regional cerebral blood flow abnormalities in depressed patients with cognitive impairment; J. Neurol. Neurosurg. Psychiatry. 1992 56 (9) 768-73]. This method enables a physician to reliably detect a parameter that seems to correlate at least in a number of cases with pathologic depression. However, treatment with anti-depressant drugs is not reflected in changes of the rCBF, which means that a therapeutic effect can not be monitored by this method.
The study of serotonine re-uptake sites using emission tomography requires the use of radioligands which have desirable properties for in vivo receptor imaging. These criteria include ease of labelling with positron-emitting radio-nucleotides, low rates of peripheral metabolism, high selectivity for brain regions holding the neuroreceptor of interest, and relatively high specific/non-specific binding ratios. Despite the development of a number of radioligands for the serotonine transporter, none of these compounds satisfactorily meet all the criteria desired for an ideal ligand.
The novel compounds and their derivatives of this invention are very specific and selective binders to serotonine transporters. This allows to reliably determine the number of serotonine binding sites and related Kd values and the release of serotonine as well as the detection of changes in the serotonine metabolism in response to therapeutic drugs.
It is therefore an object of the present invention to provide a compound which can be used in the treatment or diagnosis of diseases or disorders that are related to changes in the serotonine levels in vivo and in vitro and which can be used as well to monitor the effect of a therapy.
Further, it is an object of the present invention to provide methods for diagnosing several disorders linked to decreased or increased neurotransmission of serotonine in vivo and in vitro using a specific detectable compound.
It is an object of the present invention to provide a compound which can be used for treatment and/or diagnosing diseases or disorders that are related to changes in the serotonine levels in vivo and in vitro and which can be used as well to monitor the effect of a therapy. This object is solved by providing a labelled or unlabelled compounds derived from a compound having the formula (I): 
or any of its enantiomers or any mixture thereof, or a pharmaceutically acceptable salt thereof; wherein
n is 0 or 1;
R is hydrogen, alkyl, haloalkyl, alkenyl, haloalkenyl, alkynyl, haloalkynyl, cycloalkyl, cycloalkylalkyl or 2-hydroxyethyl, alkylthio, alkylamino or a leaving group and
R4 is
xe2x80x83phenyl which may be substituted one or more times with substituents selected from the group consisting of halogen, CF3, OCF3, CN, amino, alkylamino, nitro, alkyl, haloalkyl, hydroxyalkyl, cycloalkyl, alkenyl, haloalkenyl, alkynyl, haloalkynyl, amino, nitro, heteroaryl, aryl, xe2x80x94Oxe2x80x94Rxe2x80x3, wherein (Rxe2x80x3) represents alkyl, alkenyl, alkynyl, cycloalkyl, haloalkyl, hydroxyalkyl, aminoalkyl, haloalkenyl, haloalkynyl;
3,4-methylenedioxyphenyl;
benzyl which may be substituted one or more times with substituents selected from the group consisting of halogen, CF3, OCF3, CN, amino, alkylamino, nitro, alkyl, haloalkyl, hydroxyalkyl, cycloalkyl, alkenyl, haloalkenyl, alkynyl, haloalkenyl, amino, nitro, heteroaryl, aryl, xe2x80x94Oxe2x80x94Rxe2x80x3, wherein (Rxe2x80x3) represents alkyl, alkenyl, alkynyl, cycloalkyl, haloalkyl, hydroxyalkyl, aminoalkyl, haloalkenyl, haloalkynyl;
heteroaryl which may be substituted one or more times with substituents selected from the group consisting of halogen, CF3, OCF3, CN, amino, alkylamino, nitro, alkyl, haloalkyl, hydroxyalkyl, cycloalkyl, alkenyl, haloalkenyl, alkynyl, haloalkenyl, amino, nitro, heteroaryl, aryl, xe2x80x94Oxe2x80x94Rxe2x80x3, wherein (Rxe2x80x3) represents alkyl, alkenyl, alkynyl, cycloalkyl, haloalkyl, hydroxyalkyl, aminoalkyl, haloalkenyl, haloalkynyl;
naphthyl which may be substituted one or more times with substituents selected from the group consisting of halogen, CF3, OCF3, CN, amino, alkylamino, nitro, alkyl, haloalkyl, hydroxyalkyl, cycloalkyl, alkenyl, haloalkenyl, alkynyl, haloalkenyl, amino, nitro, heteroaryl, aryl, xe2x80x94Oxe2x80x94Rxe2x80x3, wherein (Rxe2x80x3) represents alkyl, alkenyl, alkynyl, cycloalkyl, haloalkyl, hydroxyalkyl, aminoalkyl, haloalkenyl, haloalkynyl;
a fluorescent group.
or a compound of formula (I) containing a radioactive label.
In the compound of formula (I) R is preferably hydrogen, an alkyl group having 1 to 6 C atoms, haloalkyl, haloalkenyl and R4 is preferably a phenyl group which may be substituted one or more times. The substituents are preferably selected from I, F, CF3, OCF3, CN, NO2, CH3, OCH3, or xe2x80x94Oxe2x80x94Rxe2x80x3 wherein Rxe2x80x3 represents alkyl, alkenyl, alkynyl, haloalkyl, haloalkenyl, haloalkynyl, hydroxyalkyl, aminoalkyl;
Especially preferred compounds of formula(I) are
(xc2x1)-3-(4-trifluoromethoxyphenyl)-8-methyl-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-trifluoromethoxyphenyl)-8-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-cyanophenyl)-8-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-cyanophenyl)-8-methyl-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-nitrophenyl)-8-methyl-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-nitrophenyl)-8-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-(4,4,4,3,3,2,2,1,1-nona-fluoro-butyl-1-oxy)phenyl)-8-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-(4,4,4,3,3,2,2,1,1-nona-fluoro-butyl-1-oxy)phenyl)-8-methyl-8-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-(2,2,2-trifluoroethyl-1-oxy)phenyl)-8-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-(2,2,2-trifluoroethyl-1-oxy)phenyl)-8-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-(ethylen-1-oxy)phenyl)-8-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-(ethylen-1-oxy)phenyl)-8-methyl-8-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-(2-propylen-1-oxy)phenyl)-8-azabicyclo[3.2.1]oct-2-ene; or
(xc2x1)-3-(4-(2-propylen-1-oxy)phenyl)-8-methyl-8-azabicyclo[3.2.1]oct-2-ene.
(xc2x1)3-[1-(4-trifluoromethoxyphenyl)]-9-azabicyclo[3.3.1]non-2-ene;
(xc2x1)3-[1-(4-trifluoromethylphenyl)]-9-azabicyclo[3.3.1]non-2-ene;
(xc2x1)-9-Methyl-3-[1-(4-trifluoromethoxyphenyl)]-9-azabicyclo[3.3.1]non-2-ene;
(xc2x1)-9-Methyl-3-[1-(4-trifluoromethylphenyl)]-9-azabicyclo[3.3.1]non-2-ene;
or a pharmaceutical acceptable addition salt thereof as well as the same compounds which are labelled with at least one nuclide selected from 11C, 18F and 13N, or a pharmaceutically acceptable salt of said labelled compound.
Other preferred compounds of formula (I) are compounds wherein R represents a haloalkenyl such as 1-iodo-prop-1-en-3-yl, wherein the iodine is a radioactive isotope of iodine and R4 represents phenyl substituted with xe2x80x94C4F9, xe2x80x94CH2CF3, xe2x80x94CHxe2x95x90CH2, CH2CHxe2x95x90CH2, F, CN, CH3, CF3, OCF3, Cl, H, NO2; or R4 represents 3,4-dichlorophenyl.
Further preferred compounds are compounds of formula(I) wherein R represents a haloalkyl such as methyliodine, ethyliodine, propyliodine, methylflouride, ethylfluoride, propylfluoride wherein the halogen is a radioactive isotope of iodine or fluoride and R4 represents phenyl substituted xe2x80x94C4F9, xe2x80x94CH2CF3, xe2x80x94CHxe2x95x90CH2, CH2CHxe2x95x90CH2, F, CN, CH3, CF3, OCF3, Cl, H, NO2; or R4 represents 3,4-dichlorophenyl.
Other preferred compounds are compounds of formula(I) wherein R represents a alkylthio-derivative such as thiomethyl, ethylthio, propylthio, butylthio and R4 represents phenyl substituted with xe2x80x94C4F9, xe2x80x94CH2CF3, xe2x80x94CHxe2x95x90CH2, CH2CHxe2x95x90CH2, F, CN, CH3, CF3, OCF3, Cl, H, NO2; or R4 represents 3,4-dichlorophenyl. These compounds are suitable for co-ordinating to a 99mTc complex.
Definition of Substituents
In the context of this invention halogen represents a fluorine, a chlorine, a bromine or a iodine atom.
In the context of this invention an alkyl group designates a univalent saturated, straight or branched hydrocarbon chain. The hydrocarbon chain preferably contain of from one to eighteen carbon atoms (C1-18-alkyl), more preferred of from one to six carbon atoms (C1-6-alkyl; lower alkyl), including pentyl, isopentyl, neopentyl, tertiary pentyl, hexyl and isohexyl. In a preferred embodiment alkyl represents a C1-4-alkyl group, including butyl, isobutyl, secondary butyl, and tertiary butyl. In a preferred embodiment of this invention alkyl represents a C1-3-alkyl group, which may in particular be methyl, ethyl, propyl or isopropyl.
In the context of this invention a haloalkyl group designates an alkyl as above, mono- or polysubstituted with halogen as above. This includes e.g. (X designates a halogen as above) CX3, CHX2, CH2X, CH2CX3, CH2CH2X, XCHCH2X, C3H6X, C3H5X2, C3H4X3, C3H3X4, C3H2X5, C3X7 etc. Preferred groups are C1-4-haloalkyl; Especially preferred groups are xe2x80x94CH2F, CH2I, xe2x80x94C2H5I, xe2x80x94C2H5F, C3H6I, C3H6F, xe2x80x94CF3, xe2x80x94CH2CF3, xe2x80x94C4F9.
In the context of this invention a cycloalkyl group designates a cyclic alkyl group, preferably containing of from three to seven carbon atoms (C3-7-cycloalkyl), including cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.
In the context of this invention an alkenyl group designates a carbon chain containing one or more double bonds, including di-enes, tri-enes and poly-enes. In a preferred embodiment the alkenyl group of the invention comprises of from two to six carbon atoms (C2-6-alkenyl), including at least one double bond. In a most preferred embodiment the alkenyl group of the invention is ethenyl; 1- or 2-propenyl; or 1-, 2-, or 3-butenyl.
In the context of this invention a haloalkenyl group designates a alkenyl group as above mono- or polysubstituted with halogen as above. In a preferred embodiment of the invention the haloalkenyl represents from 2 to 4 carbons monosubstituted with halogen such as xe2x80x94CH2CHxe2x95x90CHl, xe2x80x94CH2CHxe2x95x90CHF, xe2x80x94CHxe2x95x90CHF, xe2x80x94CHxe2x95x90CHl, xe2x80x94CFxe2x95x90CH2, CHxe2x95x90CF2, xe2x80x94CHxe2x95x90CHCH2I, xe2x80x94CHxe2x95x90CHCH2F, xe2x80x94CHxe2x95x90CHxe2x80x94CHxe2x95x90CHl, xe2x80x94CHxe2x95x90CHxe2x80x94CHxe2x95x90CHF, xe2x80x94CH2CH2CHxe2x95x90CHl, xe2x80x94CH2CH2CHxe2x95x90CHl, etc.
In the context of this invention an alkynyl group designates a carbon chain containing one or more triple bonds, including di-ynes, tri-ynes and poly-ynes. In a preferred embodiment the alkynyl group of the invention comprises of from two to six carbon atoms (C2-6-alkynyl), including at least one triple bond. In its most preferred embodiment the alkynyl group of the invention is ethynyl, 1,2- or 2,3-propynyl, 1,2-, 2,3- or 3,4-butynyl.
In the context of this invention a haloalkynyl group designates a alkynyl as described above, mono or poly substituted with a halogen as above. In a preferred embodiment of the invention, the haloalkynyl is an alkynyl having 2-4 carbons containing one triple bond and one halogen atom. Examples are e.g. xe2x80x94C Cxe2x80x94CH2I, xe2x80x94C Cxe2x80x94CH2F, xe2x80x94C Cxe2x80x94CH2Cl, xe2x80x94CHlxe2x80x94C CH, xe2x80x94CHFxe2x80x94C CH, xe2x80x94CHClxe2x80x94C CH, xe2x80x94CH2C Cxe2x80x94CH2I, xe2x80x94CH2C Cxe2x80x94CH2Cl, xe2x80x94CH2C Cxe2x80x94CH2F, etc.
In the context of this invention a cycloalkyl-alkyl group designates a cycloalkyl group as defined above, which cycloalkyl group is substituted on an alkyl group as also defined above. Examples of preferred cycloalkyl-alkyl groups of the invention include cyclopropylmethyl and cyclopropylethyl.
In the context of this invention an alkoxy group designates an xe2x80x9calkyl-Oxe2x80x94xe2x80x9d group, wherein alkyl is as defined above.
In the context of this invention an haloalkoxy group represents an alkoxy group as above substituted with one or more halogens as above.
In the context of this invention an alkoxy-alkyl group designates an xe2x80x9calkyl-O-alkylxe2x80x94xe2x80x9d group, wherein alkyl is as defined above.
In the context of this invention an amino group may be a primary (xe2x80x94NH2), secondary (xe2x80x94NH-alkyl), or tertiary (xe2x80x94N(alkyl)2) amino group, i.e. it may be substituted once or twice with an alkyl group as defined above.
In the context of this invention an alkylamino group is -alkyl-NH2, alkyl-NH-alkyl or alkyl-N(alkyl)2 wherein alkyl is as defined above.
In the context of this invention an alkylthio group is alkyl-SH, wherein alkyl is as defined above.
Examples of preferred aromatic heterocyclic monocyclic groups of the invention include 1,3,2,4- or 1,3,4,5-dioxadiazolyl, dioxatriazinyl, dioxazinyl, 1,2,3-, 1,2,4-, 1,3,2- or 1,3,4-dioxazolyl, 1,3,2,4- or 1,3,4,5-dithiadiazolyl, dithiatriazinyl, dithiazinyl, 1,2,3-dithiazolyl, furanyl, furazanyl, imidazolyl, isoimidazolyl, 2-isoimidazolyl, isoindazolyl, isothiazolyl, isoxazolyl, 1,2,3-, 1,2,4-, 1,2,5- or 1,3,4-oxadiazolyl, oxatetrazinyl, oxatriazinyl, 1,2,3,4- or 1,2,3,5-oxatriazolyl, oxazolyl, pyrazinyl, pyrazolyl, pyridazinyl, pyridinyl, pyrimidinyl, pyrrolyl (azolyl), 1,2,3,4- or 2,1,3,4-tetrazolyl, thiadiazolyl, thiazolyl, thienyl, 1,2,3-, 1,2,4- or 1,3,5-triazinyl, and 1,2,3-, 1,2,4-, 2,1,3- or 4,1,2-triazolyl, furan-2-yl, furan-3-yl, 2-, 4- or 5-imidazolyl, 3-, 4- or 5-isoxazolyl, 1-, 2- or 3-pyridinyl, 1- or 2-thienyl.
In the context of this application, xe2x80x9clabelxe2x80x9d stands for the binding of a marker to the compound of interest that will allow easy quantitative detection of said compound.
The labelled compound of the present invention preferably contains at least one radionuclide as a label. Positron emitting radionuclides are all candidates for usage. In the context of this invention the radionuclide is preferably selected from 11C, 18F, 15O, 13N, 123I, 125I, 131I, 3H and 99mTc.
The fluorescent group of the compound of formula (I) can be selected from the group of naturally occurring fluorophores or chemically synthesized fluorescent groups, such as rhodamine, green fluorescent protein or fluorescein and its derivatives.
It will be appreciated by those skilled in the art that some compounds of formula (I) contain chiral centres and that such compounds exist in the form of isomers (i.e. enantiomers). The invention includes all such isomers and any mixtures thereof including racemic mixtures.
Some of the compounds of formula (I) exist in (+) and (xe2x88x92) forms as well as in racemic forms. Racemic forms can be resolved into the optical antipodes by known methods, for example, by separation of diastereomeric salts thereof with an optically active acid, and liberating the optically active amine compound by treatment with a base. Another method for resolving racemates into the optical antipodes is based upon chromatography on an optically active matrix. Racemic compounds of the present invention can thus be resolved into their optical antipodes, e.g., by fractional crystallisation of d- or I-(tartrates, mandelates, or camphorsulphonate) salts. The compounds of formula (I) may also be resolved by the formation of diastereomeric amides by reaction of the compounds of formula (I) with an optically active activated carboxylic acid such as that derived from (+) or (xe2x88x92) phenylalanine, (+) or (xe2x88x92) phenylglycine, (+) or (xe2x88x92) camphanic acid or by the formation of diastereomeric carbamates by reaction of the compounds of formula (I) e.g. with an optically active chloroformate.
Additional methods for the resolvation of optical isomers, known to those skilled in the art may be used, and will be apparent to the average person skilled in the art. Such methods include those discussed by Jaques J, et al. [Jaques J. Collet A, and Wilen S; in Enantiomers, Racemates, and Resolutions, John Wiley and Sons, New York, 1981].
The labelled compounds of the invention may be prepared in numerous ways. The labelled compounds of the invention and their pharmaceutically acceptable derivatives may thus be prepared by any method known in the art for the preparation of compounds of analogous structure, provided that a label, preferably a radionuclide, is incorporated by suitable means.
The labelled compounds of the present invention can be prepared in the same way as the unlabelled compounds of formula (I) except that at least one of the materials used for the preparation of the compounds of formula (I) comprises a label, preferably a radionuclide, which label is inserted into the final compound. Alternatively, a group of an unlabelled compound of formula (I) can be exchanged by a labelled group, thereby forming a labelled compound of formula (I).
The unlabelled compounds of formula (I) can for example be prepared according to the methods disclosed in WO 97/13770, for example as in the following scheme (1). 
The non-ene derivatives are prepared by essentially analogous methods of preparation.
The substituents R and R4 in the formulae of scheme (I) are as defined above and X is Li, MgBr or any other type of functional group suitable for generating a carbanion as its counterpart.
The processes in the reaction scheme above are carried out in conventional manner. The dehydration of the alcohol is affected using acids such as hydrochloric or sulphuric acid or other conventional dehydrating agents such as for example P2O5 or SOCl2.
An unlabelled compound of formula (I) can be converted to another unlabelled compound of formula (I) using conventional methods.
The materials used in the preparation of unlabelled compounds of formula (I) are known or can be prepared by known processes from commercially available materials.
The products of the reactions described herein can be isolated by conventional means, such as extraction, crystallisation, distillation and/or chromatography.
The labelled compounds of formula (I) can generally be prepared in the same way as described above for the unlabelled compounds of formula (I). In this case, any of the materials used for the preparation of the unlabelled compound of formula (I) can be labelled, preferably by a radionuclide, in such a way that the label is incorporated into the finally prepared labelled compound of formula (I). Said labelled materials are either commercially available or can be prepared by using commercially available labelling agents.
An examples of commercially available labelling agents, which can be used in the preparation of the labelled compounds of the present invention is [11C]O2. 18F, Nal with different isotopes of iodine.
In particular [C11]O2 may be converted to a [11C]-methylating agent, such as [11C]H3I or [11C]-methyl triflate.
Labelled compounds containing e.g. [125I]labelled 1-iodoprop-1-en-3-yl as substituent on N-8 may be prepared as described in the art [Elmaleh et. al.; J. Nucl. Med. 1996 37 1197-1202].
Labelled compounds containing e.g. [18F]-alkyl substituted N-8 may be prepared as described in the art, e.g. in WO 96/39198.
Furthermore, labelled compounds of the present invention can, for example, be prepared by using labelled compounds R4X in the reaction shown in scheme (1) above, wherein R4 and X are as defined above, except that R4 contains a label. These compounds can be prepared by known methods. Illustrative examples of labelled compounds R4X are those, wherein R4 is selected from [11C]H3-substituted phenyl, benzyl, heteroaryl and naphthyl groups, [11C]F3-substituted phenyl, benzyl, heteroaryl and naphthyl groups, [11C]N-substituted phenyl, benzyl, heteroaryl and naphthyl groups, H3[11C]O-substituted phenyl, benzyl, heteroaryl and naphthyl groups, [18F]-substituted phenyl, benzyl, heteroaryl and naphthyl groups, [18F]3C-substituted phenyl, benzyl, heteroaryl and naphthyl groups, H3C[15O]-substituted phenyl, benzyl, heteroaryl and naphthyl groups, a 3,4-methylenedioxyphenyl group containing at least one [15O], N[15O]2-substituted phenyl, benzyl, heteroaryl and naphthyl groups, C[13N]-substituted phenyl, benzyl, heteroaryl and naphthyl groups, [13N]amino-substituted phenyl, benzyl, heteroaryl and naphthyl groups, [123I], [125I] or [131I]-substituted phenyl, benzyl, heteroaryl and naphthyl groups and substituted or unsubstituted phenyl, benzyl, heteroaryl and naphthyl groups containing at least one [3H] attached to the ring or contained in a substituted group.
As described above, an unlabelled compound of formula (I) can be converted to a labelled compound of formula (I) by using a labelling agent.
A labelled compound according to the present invention containing a [11C]H3-group can, for example, be prepared by reacting a free amine compound of formula (I), i.e. wherein R is H and R4 is as defined above, with a [11C]-methylating agent, preferably with [11C]H3I or [11C]-methyl triflate.
In analogy, other[11C] labelled groups R can be introduced, e.g. by reacting said free amine compound of formula (I) with a [11C] labelled alkylating agent optionally derivatised with a suitable leaving group (LG), such as [11C]-cyclohexyl triflate or another suitable cycloalkyl alkylating agent. Other types of labelling of R of formula (I) includes e.g. alkyl substituted with [125I]; alkenyl substituted with [125I); e.g. (1-[125I]-prop-1-en-3-yl) as described in the art, (1-[125I]-but-1-en-3-yl); and alkynyl substituted with [125I]; or alkyl substituted with [18F], alkenyl substituted with [18F], alkynyl substituted with [18F]; Standard leaving groups for use in these types of reaction are known in the art and some examples are mentioned below. Optionally the reaction may proceed through intermediate compounds such as the trialkyl tin derivatives, which is displaced by addition of Na[125I] or [18F].
In analogy, other labelled groups can be introduced to the R group e.g. by derivatising said free amine compound of formula (I), to contain a suitable leaving group which can be displaced by a labelled nucleofile. The leaving group being e.g. esters of sulphuric and sulfonic acids in general such as mesylate, tosylate, brosylate, nosylate, triflate, nonaflates, tresylates; Esters of nitrous acid, and inorganic ester leaving groups such as ROPO(OH)2, ROB(OH)2 halogen, conjugate acid of alcohol, ether, quarternary amines, tertiary sulphides, trialkyl tin derivatives etc., all known in the art; Performing the reaction in a suitable solvent, preferable polar, aprotic solvent and preferably essential free of water, with a labelled agent, acting as a nucleofile. Such nucleofile, as e.g. [18F], may require auxiliary reagents to dissolve in the solvent. An auxiliary agent of the form M+Xxe2x88x92, M+ being i.e. 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane, alkali metal ions, tetraalkyammonium etc. as described in the art, and Xxe2x88x92 being e.g. carbonate, bicarbonate, hydroxide, formate or another counter ion, capable of dissolving radionuclides. Such compounds are known in the art.
As yet another embodiment of the invention, the compounds of formula(I) can represent substituents capable of coordinating to a metal complex. Such a metal could be isotopes of Tc whereby the complete complex formation is radiolabelled and suitable for diagnostic use [Meegall, S, et al.; Bioconjugate Chem. 1996 7 421-429]. Such substituents are e.g., alkylthio, alkenylthio, and alkynylthio.
The preparation of the labelled compounds according to the present invention is further illustrated by the working examples described below (Preparative Examples 1-4).
The present invention further provides a pharmaceutical composition comprising a diagnostically effective amount of the labelled compound of formula (I) or mixtures thereof together with at least one pharmaceutically acceptable carrier or diluent, wherein the labelled compound of formula (I) is defined as disclosed above. The carrier or diluent must be xe2x80x9cacceptablexe2x80x9d in the sense of being compatible with the other ingredients of the formulation and not deleterious to the recipient thereof and is not specifically limited.
Pharmaceutical formulations include those suitable for parenteral administration, including intramuscular, sub-cutaneous and intravenous administration. Intravenous injection is the preferred way of administration.
Liquid form preparations include solutions, suspensions, and emulsions, for example, water or water-propylene glycol solutions. For example, parenteral injection liquid preparations can be formulated as solutions in aqueous polyethylene glycol solution.
The labelled compounds of the present invention may thus be formulated for parenteral administration (e.g. by injection) and may be presented in unit dose form in ampoules, pre-filled syringes, small volume infusion or in multi-dose containers with an added preservative. The compositions may take such forms as suspensions, solutions, or emulsions in oily or aqueous vehicles, and may contain formulatory agents such as suspending, stabilising and/or dispersing agents. Alternatively, the active ingredient may be in powder form, obtained by aseptic isolation of sterile solid or by lyophilisation from solution, for constitution with a suitable vehicle, e.g. sterile, pyrogen-free water, before use.
Aqueous solutions suitable for oral use can be prepared by dissolving the labelled compound of the present invention in water and adding suitable colorants, flavours, stabilising and thickening agents, as desired.
Aqueous suspensions suitable for oral use can be made by dispersing the finely divided labelled compound of the present invention in water with viscous material, such as natural or synthetic gums, resins, methylcellulose, sodium carboxymethylcellulose, or other well known suspending agents.
Also included are solid form preparations which are intended to be converted, shortly before use, to liquid form preparations for oral administration. Such liquid forms include solutions, suspensions, and emulsions. In addition to the labelled compound of the present invention, these preparations may, for example, contain colorants, flavours, stabilisers, buffers, artificial and natural sweeteners, dispersants, thickeners, and/or solubilizing agents.
Alternatively, the active ingredients may be provided in the form of a dry powder, for example a powder mix of the labelled compound of the present invention in a suitable powder base, such as lactose, starch, starch derivatives such as hydroxypropylmethyl cellulose and polyvinylpyrrolidone (PVP). The powder composition may be presented in unit dose form for example in capsules or cartridges of, e.g., gelatine, or blister packs.
Preferred compositions are tablets or capsules for oral administration and liquids for intravenous administration.
Suitable dosage ranges are in the range of from about 0.1 ng to about 100 xcexcg of the labelled compounds of the present invention, administered in an appropriate dose, dependent as usual upon the exact mode and form of administration, the type of diagnosis, the subject involved and the body weight of the subject involved, and further the preference and experience of the physician or veterinarian in charge.
In further embodiments, the invention relates to
The use of a compound as above for the manufacture of a medicament for the treatment of a disorder or disease of a living animal body, including a human, which disorder or disease is responsive to the inhibition of monoamine neurotransmitter re-uptake in the central nervous system;
The use of a compound as above for the manufacture of a medicament for the treatment of a disorder or disease of a living animal body, including a human, which disorder or disease is responsive to the inhibition of serotonine re-uptake in the central nervous system;
The use of a compound as above for the manufacture of a medicament for the treatment of depression and related disorders such as pseudodementia or Ganser""s syndrome, obsessive compulsive disorders, panic disorders, memory deficits, attention deficit hyperactivity disorder, obesity, anxiety and eating disorders; and
The use as above wherein the compound employed is
(xc2x1)-3-(4-trifluoromethoxyphenyl)-8-methyl-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-trifluoromethoxyphenyl)-8-azabicyclo[3.2.1)oct-2-ene;
(xc2x1)-3-(4-cyanophenyl)-8-azabicyclo(3.2.1]oct-2-ene;
(xc2x1)-3-(4-cyanophenyl)-8-methyl-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-nitrophenyl)-8-methyl-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-nitrophenyl)-8-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-(4,4,4,3,3,2,2,1,1-nona-fluoro-butyl-1-oxy)phenyl)-8-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-(4,4,4,3,3,2,2,1,1-nona-fluoro-butyl-1-oxy)phenyl)-8-methyl-8-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-(2,2,2-trifluoroethyl-1-oxy)phenyl)-8-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-(2,2,2-trifluoroethyl-1-oxy)phenyl)-8-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-(ethylen-1-oxy)phenyl)-8-azabicyclo(3.2.1]oct-2-ene;
(xc2x1)-3-(4-(ethylen-1-oxy)phenyl)-8-methyl-8-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-(2-propylen-1-oxy)phenyl)-8-azabicyclo[3.2.1]oct-2-ene; or
(xc2x1)-3-(4-(2-propylen-1-oxy)phenyl)-8-methyl-8-azabicyclo[3.2.1]oct-2-ene.
(xc2x1)3-[1-(4-trifluoromethoxyphenyl)]-9-azabicyclo[3.3.1]non-2-ene;
(xc2x1)3-[1-(4-trifluoromethylphenyl)]-9-azabicyclo[3.3.1]non-2-ene;
(xc2x1)-9-Methyl-3-[1-(4-trifluoromethoxyphenyl)]-9-azabicyclo[3.3.1]non-2-ene;
(xc2x1)-9-Methyl-3-[1-(4-trifluoromethylphenyl)]-9-azabicyclo[3.3.1]non-2-ene;
or a pharmaceutically acceptable addition salt thereof;
A method of treating a disorder or disease of a living animal body, including a human, which disorder or disease is responsive to the inhibition of monoamine neurotransmitter re-uptake, comprising the step of administering to such a living animal body, including a human, in need thereof a therapeutically effective amount of a compound as above;
A method of treating a disorder or disease of a living animal body, including a human, which disorder or disease is responsive to the inhibition of serotonine re-uptake, comprising the step of administering to such a living animal body, including a human, in need thereof a therapeutically effective amount of a compound as above;
The method as above wherein depression and related disorders such as pseudodementia or Ganser""s syndrome, obsessive compulsive disorders, panic disorders, memory deficits, attention deficit hyperactivity disorder, obesity, anxiety or eating disorders are treated.
The compounds of the invention have been tested for their ability to inhibit reuptake of dopamine(DA) noradrenaline(NA) and serotonine(5-HT) in synaptosomes.
Background:
Specific neurotransmitter transporters/uptake sites on nerve terminals presumably function to terminate neuronal signalling by removing the neurotransmitters dopamine, noradrenaline and serotonine, respectively, from the synaptic cleft. The activity of the transporter integral proteins can be measured in vitro by synaptosomal uptake of 3H-dopamine, 3H-noradrenaline and 3H-serotonine, respectively.
Tissue preparations: Preparations are performed at 0-4xc2x0 C. unless otherwise indicated. Corpi striati from male Wistar rats (150-200 g) are homogenised for 5-10 sec in 100 volumes of ice-cold 0.32M sucrose containing 1 mM pargyline using an Ultra-Turrax homogenizer. Monoamine oxidase activity will be inhibited in the presence of pargyline. The homogenate is centrifuged at 1000xc3x97g for 10 min. The resulting supernatant is then centrifuged at 27,000xc3x97g for 50 min and the supernatant is discarded. The pellet (P2) is resuspended in oxygenated (equilibrated with an atmosphere of 96% O2: 4% CO2 for at least 30 min) Krebs-Ringer incubation buffer (8000 ml per g of original tissue) at pH 7.2 containing 122 mM NaCl, 0.16 mM EDTA, 4.8 mM KCl, 12.7 mM Na2HPO4, 3.0 mM NaH2PO4, 1.2 mM MgSO4, 1 mM CaCl2, 10 mM glucose and 1 mM ascorbic acid.
Assay: Aliquots of 4.0 ml tissue suspension are added to 100 xcexcl of test solution and 100 xcexcl of 3H-DA (1 nM, final concentration), mixed and incubated for 25 min at 37xc2x0 C. Non-specific uptake is determined using benztropine (10 xcexcM, final concentration). After incubation the samples are poured directly onto Whatman GF/C glass fibre filters under suction. The filters are then washed three times with 5 ml of ice-cold 0.9% (w/v) NaCl solution. The amount of radioactivity on the filters is determined by conventional liquid scintillation counting. Specific uptake is calculated as the difference between total uptake and non-specific uptake.
25-75% inhibition of specific binding must be obtained, before calculation of an IC50.
The test value is given as IC50 (the concentration (xcexcM) of the test substance which inhibits the specific binding of 3H-DA by 50%).
Tissue preparation: Preparations are performed at 0-4xc2x0 C. unless otherwise indicated. Hippocampi from male Wistar rats (150-200 g) are homogenised for 5-10 sec in 100 volumes of ice-cold 0.32M sucrose containing 1 mM pargyline using an Ultra-Turrax homogenizer. Monoamine oxidase activity will be inhibited in the presence of pargyline. The homogenate is centrifuged at 1000xc3x97g for 10 min. The resulting supernatant is then centrifuged at 27,000xc3x97g for 50 min and the supernatant is discarded. The pellet (P2) is resuspended in oxygenated (equilibrated with an atmosphere of 96% O2: 4% CO2 for at least 30 min) Krebs-Ringer incubation buffer (2000 ml per 9 of original tissue) at pH 7.2 containing 122 mM NaCl, 0.16 mM EDTA, 4.8 mM KCl, 12.7 mM Na2HPO4, 3.0 mM NaH2PO4, 1.2 mM MgSO4, 0.97 mM CaCl2, 10 mM glucose and 1 mM ascorbic acid.
Assay: Aliquots of 4.0 ml tissue suspension are added to 100 xcexcl of test solution and 100 xcexcl of 3H-NA (1 nM, final concentration), mixed and incubated for 90 min at 37xc2x0 C. Non-specific uptake is determined using desipramine (1 xcexcM, final concentration). After incubation the samples are poured directly onto Whatman GF/C glass fibre filters under suction. The filters are then washed three times with 5 ml of ice-cold 0.9% (w/v) NaCl solution. The amount of radioactivity on the filters is determined by conventional liquid scintillation counting. Specific uptake is calculated as the difference between total uptake and non-specific uptake.
25-75% inhibition of specific binding must be obtained, before calculation of an IC50.
The test value is given as IC50 (the concentration (xcexcM) of the test substance which inhibits the specific binding of 3H-NA by 50%).
Tissue Preparation: Preparations are performed at 0-4xc2x0 C. unless otherwise indicated. Cerebral cortices from male Wistar rats (150-200 g) are homogenised for 5-10 sec in 100 volumes of ice-cold 0.32M sucrose containing 1 mM pargyline using an Ultra-Turrax homogenizer. Monoamine oxidase activity will be inhibited in the presence of pargyline. The homogenate is centrifuged at 1000xc3x97g for 10 min. The resulting supernatant is then centrifuged at 27,000xc3x97g for 50 min and the supernatant is discarded. The pellet (P2) is resuspended in oxygenated (equilibrated with an atmosphere of 96% O2: 4% CO2 for at least 30 min) Krebs-Ringer incubation buffer (1000 ml per g of original tissue) at pH 7.2 containing 122 mM NaCl, 0.16 mM EDTA, 4.8 mM KCl, 12.7 mM Na2HPO4, 3.0 mM NaH2PO4, 1.2 mM MgSO4, 1 mM CaCl2, 10 mM glucose and 1 mM ascorbic acid.
Assay: Aliquots of 4.0 ml tissue suspension are added to 100 xcexcl of test solution and 100 xcexcl of 3H-5-HT (1 nM, final concentration), mixed and incubated for 30 min at 37xc2x0 C. Non-specific uptake is determined using citalopram (1 xcexcM, final concentration). After incubation the samples are poured directly onto Whatman GF/C glass fibre filters under suction. The filters are then washed three times with 5 ml of ice-cold 0.9% (w/v) NaCl solution. The amount of radioactivity on the filters is determined by conventional liquid scintillation counting. Specific uptake is calculated as the difference between total uptake and non-specific uptake.
25-75% inhibition of specific binding must be obtained, before calculation of an IC50.
The test value is given as IC50 (the concentration (xcexcM) of the test substance which inhibits the specific binding of 3H-5-HT by 50%).
Test results obtained by testing a selected compound of the present invention appear from the below tables.
The results presented above show that the compounds are in vitro inhibitors of monoamine neurotransmitter re-uptake, in particular selective serotonine re-uptake inhibitors.
The results shown in Table 2 obtained in vitro show that 3-(4-trifluoromethoxyphenyl)-8-methyl-8-azabicyclo[3.2.1]oct-2-ene (racemate) and 3-(4-trifluoromethoxyphenyl)-8-azabicyclo[3.2.1]oct-2-ene (racemate) are highly potent and selective serotonine re-uptake inhibitors. Both racemic compounds were significantly more potent as inhibitors of serotonine uptake than of either noradrenaline or dopamine uptake. It is noteworthy that the 3000-fold greater potency of the compounds as inhibitors of serotonine uptake than of either noradrenaline or dopamine uptake places them among the most selective serotonine re-uptake inhibitors currently known. There were no marked differences in vitro between the actions of the enantiomers of 3-(4-trifluoromethoxyphenyl)-8-azabicyclo[3.2.1]oct-2-ene and further studies also showed the same for the enantiomers of 3-(4-trifluoromethoxyphenyl)-8-methyl-8-azabicyclo[3.2.1]oct-2-ene.
The compounds of the invention have also been tested in the following test for antidepressant activity.
The second object of the present invention is attained in a first embodiment of the invention by a method for determining the level of monoamine neurotransmitter re-uptake sites in a blood sample, said method comprising the steps of
(a) adding a compound of formula (I) or any of its enantiomers or a mixture thereof, or a pharmaceutically acceptable salt thereof in labelled or unlabelled form to a blood sample;
(b) measuring an amount of a compound of formula (I) bound to a predetermined part of the blood sample; and
(c) calculating the number of the monoamine neurotransmitter re-uptake sites in blood platelets from the data obtained in (b).
In the following, this method is also referred to as the xe2x80x9cin-vitro methodxe2x80x9d of the present invention.
The in-vitro method especially allows to accurately calculate the serotonine re-uptake sites in a cellular fraction obtained in step (b). The predetermined part of the blood sample is preferably a blood fraction that contains the blood platelets.
In step (2) of the in-vitro method of the present invention a labelled or unlabelled compound of formula (I) or any of its enantiomers or a mixture thereof, or a pharmaceutically acceptable salt thereof is added to a blood sample. Generally, the compound of formula (I) added in step (a) is selected depending on the method of measuring the amount of the compound of formula (I) bound to said predetermined part of the blood sample used in step (b) of the in-vitro method of the invention.
In case a compound of formula (I) used in step (a) of the above mentioned method is a labelled compound of the present invention, this compound is preferably labelled with at least one radionuclide. Preferred radionuclides are those described above. In formula (I), R and R4 are as defined above, and preferred groups R and R4 are as defined above. Additionally, R4 being a fluorescent group is preferred.
In step (a) of the in-vitro method of the present invention the compound of formula (I) may also be used in unlabelled form. In this case, R and R4 are as defined above, and preferred groups R and R4 are as defined above. Additionally, R4 being a fluorescent group is preferred.
The labelled or unlabelled compound of formula (I) added in step (a) of the in vitro-method of the present invention can be detected by a suitable spectroscopic method, in particular UV spectroscopy and/or fluorescence spectroscopy.
In step (c) of the in-vitro method of the present invention, the level of the monoamine neurotransmitter re-uptake sites can be calculated from the data obtained in step (b) by using, for example, Scatchard Plot Analysis.
In a second embodiment, the second object of the present invention is solved by a method for the non-invasive determination of the distribution of a tracer compound inside a whole, intact living animal or human body using a physical detection method, wherein the tracer compound is a compound of formula (I) or any of its enantiomers and any mixture thereof, or a pharmaceutically acceptable salt thereof in its labelled or unlabelled form.
In the following, this method is also referred to as xe2x80x9cin-vivo methodxe2x80x9d of the present invention.
The physical method for detecting said tracer compound of formula (I) in the in-vivo method of the present invention is preferably selected from Position Emission Tomography (PET), Single Photon Imaging Computed Tomography (SPECT), Magnetic Resonance Spectroscopy (MRS), Magnetic Resonance Imaging (MRI), and Computed Axial X-ray Tomography (CAT), or combinations thereof.
The tracer compound of formula (I) can be selected in accordance with the detection method chosen. The compound of formula (I) as described above can be used in labelled form or in unlabelled form.
In case a labelled compound of formula (I) is used in the in-vivo method of the present invention, it is preferably labelled with a radionuclide, which is preferably selected from 11C, 18F, 15O, 13N, 123I, 125I, 131I and 3H. Preferred examples of the labelled compound of formula (I) according to the present invention are given above.
The following table summarises preferred detection methods and the use of suitable radionuclides.
In case an unlabelled compound of formula (I) is used in the in-vivo method of the present invention, said compound preferably contains at least one 19F containing substituent. Especially preferred unlabelled compounds of formula (I) are those, wherein R4 is a phenyl group containing at least one substituent selected from OCF3, CN and NO2.
Specific examples of unlabelled compounds of formula (I) which can be used in the in-vivo method of the present invention are
(xc2x1)-3-(4-trifluoromethoxyphenyl)-8-methyl-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-trifluoromethoxyphenyl)-8-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-cyanophenyl)-8-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-cyanophenyl)-8-methyl-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-nitrophenyl)-8-methyl-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-nitrophenyl)-8-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-(4,4,4,3,3,2,2,1,1-nona-fluoro-butyl-1-oxy)phenyl)-8-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-(4,4,4,3,3,2,2,1,1-nona-fluoro-butyl-1-oxy)phenyl)-8-methyl-8-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-(2,2,2-trifluoroethyl-1-oxy)phenyl)-8-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-(2,2,2-trifluoroethyl-1-oxy)phenyl)-8-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-(ethylen-1-oxy)phenyl)-8-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-(ethylen-1-oxy)phenyl)-8-methyl-8-azabicyclo[3.2.1]oct-2-ene;
(xc2x1)-3-(4-(2-propylen-1-oxy)phenyl)-8-azabicyclo[3.2.1]oct-2-ene; or
(xc2x1)-3-(4-(2-propylen-1-oxy)phenyl)-8-methyl-8-azabicyclo[3.2.1]oct-2-ene.
(xc2x1)3-[1-(4-trifluoromethoxyphenyl)]-9-azabicyclo[3.3.1]non-2-ene;
(xc2x1)3-[1-(4-trifluoromethylphenyl)]-9-azabicyclo[3.3.1]non-2-ene;
(xc2x1)-9-Methyl-3-[1-(4-trifluoromethoxyphenyl)]-9-azabicyclo[3.3.1]non-2-ene;
(xc2x1)-9-Methyl-3-[1-(4-trifluoromethylphenyl)]-9-azabicyclo[3.3.1]non-2-ene;
or a pharmaceutically acceptable salt thereof.
Examples of physical detection methods which can be used for detecting unlabeled compounds of formula (I) are HPLC and Mass spectroscopy.
The compound of formula (I) or any of its enantiomers or any mixtures thereof in labelled or unlabelled form can be used as a diagnostic agent for the diagnosis of a disorder or disease of a living animal body, including a human, which disorder or disease is responsive to the inhibition of monoamine neurotransmitter re-uptake in the central nervous system. Especially preferred is the use of these compounds for the diagnosis of a disorder or disease which is responsive to the inhibition of serotonine neurotransmitter re-uptake. Furthermore, said labelled or unlabelled compound of formula (I) can be used for diagnosing a disorder or disease which is depression or a related disorder, such as pseudodementia or Ganser""s syndrome, obsessive compulsive disorder, panic disorder, memory deficit, attention deficit hyperactivity disorder (ADHD syndrome), obesity, anxiety and eating disorder.
Before conducting the in-vivo method of the present invention, a diagnostically effective amount of a labelled or unlabeled compound of formula (I) is administered to a living body, including a human. Although the labelled or unlabelled compound of formula (I) can be administered as such, it is preferably administered in the form of a pharmaceutical composition.
In case a labelled compound of formula (I) is administered in the form of a pharmaceutical composition, the pharmaceutical composition of the present invention as described above can be used.
In case an unlabelled compound of formula (I) is administered in the form of a pharmaceutical composition, a pharmaceutical composition may be used, which differs from the above described pharmaceutical composition of the present invention in that it contains an unlabelled compound of formula (I) instead of the labelled compound of formula (I).
The diagnostically effective amount of the labelled or unlabelled compound of formula (I) to be administered before conducting the in-vivo method for the present invention is within a range of from 0.1 ng to 100 mg per kg body weight, preferably within a range of from 1 ng to 10 mg per kg body weight.
By using the in-vivo method of the present invention the distribution of said labelled or unlabelled compound of formula (I) can be determined by a physical method in the body or any desired part thereof. Preferably, the distribution in a part of the nervous system, especially preferred in the brain, is determined.
From the data obtained from the in-vivo method of the present invention, the extent of disease can be evaluated e.g. by a physician, preferably a neurologist. Said evaluation can especially be effected by comparing the data obtained from the in-vivo method of the present invention with control data. Said control data may, for example, be obtained from a control group of individuals. This group consists either of healthy individuals or of individuals who suffer from one of the above mentioned disorders or diseases.
Thus, the present invention further provides a method of diagnosis of a disorder or disease of a living human or animal body, which disorder or disease is responsive to the inhibition or monoamine neurotransmitter re-uptake, comprising the steps of
(a) administering to said body a diagnostically effective amount of a compound of formula (I) in its labelled or unlabelled form,
(b) detecting said compound and determining the distribution thereon in at least a part of said body by physical methods, and
(c) comparing the obtained data with control data.
The pharmaceutical composition, which is preferably used in the in-vitro method of the present invention, can be provided in the form of an assay kit system wherein said pharmaceutical composition comprises either a labelled or unlabelled compound of formula (I) in unit-dosage form in a suitable container. Preferably, said unit dosage is adjusted to be sufficient for analysing one blood sample according to the in-vitro method of the invention. Furthermore, said assay kit of the present invention can further comprise a stabilising composition. The stabilising composition can be selected from antioxidants, such as Ascorbic Acid, or from buffers of weak acid-base composition e.g. phosphate buffers or from various types of cyclodextrins e.g. Hydroxypropyl xcex2-Cyclodextrin.
The compounds and their derivatives of this invention are the first substances known that specifically bind to serotonine transporters. The compounds and their derivatives of this invention have a high selectivity for serotonine transporters and this applies specifically to the compounds given in the examples below, more specifically to compounds of formula (I), where R4 is a phenyl group containing at least one substituent selected from OCF3,CN and NO2 and even more specifically to compounds of formula (I), where R4 is a phenyl group substituted with at least one OCF3 group.
This allows for the first time to reliably determine the number of serotonine binding sites and related Kd values and the release of serotonine as well as the detection of changes in the serotonine metabolism in response to therapeutic drugs.
Furthermore, a labelled compound of formula (I) may also be used in the analysis and adjustment of the treatment of patients having a lower level of serotonine re-uptake as compared to the normal level with serotonine uptake inhibitors. In this context, the compounds of the invention can be employed to assess whether the dosage of serotonine re-uptake inhibitors given is sufficient to occupy a high number of the serotonine transporter sites thereby blocking the re-uptake of serotonine and extending their presence and action within the synaptic cleft. The labelled compound of the invention can likewise be used to investigate whether an unnecessary high dose is given thereby blocking too many serotonine transporter sites and/or increasing the risk of unwanted side-effects. If a compound is given in a sufficient dose whereby maximal blocking of serotonine re-uptake is achieved, then higher doses will only increase the risk of side effects.